introduction

these are affordable super wide angle manual focus lenses for full frame cameras giving a field of view of 115.7° but also comes in cropped sensor mounts giving field of views 93.9° on DX, 89.9° on APS-C, and 76.24° on Micro Four Thirds system

fixed petal lens hood

NO ability to use filters!

the f/2.8 UMC lens is popular for astrophotographic landscapes of the Milky Way as photographers like its field of view on full frame, wide aperture, and don't need AF, and it gives nicer edge-to-edge star images with minimal coma/astigmatism, better than Canon or Nikon branded very expensive alternatives, BUT the original version has been criticised for not being as sharp and for having more distortion, and it only has 6 straight diaphragm blades

original version released late 2009 Samyang 14 mm f/2.8 IF ED MC Aspherical

it was soon released as an updated version Samyang 14 mm f/2.8 ED AS IF UMC which is similar design but has the UMC lens coatings, is sharper, better into the light, less coma and astigmatism (only 1% not 10%), a little more CA and distortion

a newer AE version adds electronic contacts for EXIF, and AF confirm on dSLRs

the T3.1 VDSLR II lens is a a touch more expensive, with different optical design, much heavier, and is designed for Cine/video use but has 8 rounded blades for nicer out of focus image shapes stopped down, and presumably nicer star burst imagery stopped down.

specs compared

Samyang XP 14mm f/2.4

Samyang 14mm f/2.8 IF ED UMC Asph lens

Samyang 14mm T3.1 VDSLR II lens

price on Amazon.com

$US799

$US299/359

$US399

build

plastic/metal

aluminium alloy

aperture

f/2.4

f/2.8

T3.1

diaphragm blades

9 rounded

6 straight

8 rounded

stepless, quiet aperture ring

No ring

No

Yes

Cine gearing

No

Yes

close focus

0.28m

0.28m

0.28m

MF gearing

slow, more precise than needed

filter thread

None!

None!

None!

rear filter slot

None!

None!

None!

infrared marker

No

No

No

DOF scale

No

No

No

electronic contacts

Yes

No/Yes AE version

No

optical design

18 elements in 14 groups, 2ASPH, hybrid, 2ED, 3HR

14 elements in 12 groups, ASPH, UD, hybrid, 2UD, 3HR

14 elements in 10 groups, ASP, hybrid ASPH, HR ED

coating

UMC

UMC

resolution

sharp, best at f/4-5.6

sharp centres best at f/5.6 but soft edges improve marginally stopping down